Pneumatics & Brake System

Question 1

What is Main Reservoir operating pressure? +-20

Answer 1

850-1000kPa

Question 2

What is Emergency BC pressure?

Answer 2

280-460kPa

Question 3

What is Maximum BC Pressure

Answer 3

250-380kPa

Question 4

What is Holding BC Pressure

Answer 4

140-240kPa

Question 5

What is Main Reservoir safety valve pressure?

Answer 5

1050kPa

Question 6

What is Main Reservoir Safety Loop activation pressure?

Answer 6

600kPa

Question 7

What is the ASU?

Answer 7

Air Supply Unit

Air Supply Unit Equipment Case
(not required to be inspected)

Question 8

What does the ASU consist of?

Answer 8

Main air compressor

Air Dryers

Filters

Backup Compressor Governor

Question 9

How many air compressors does a 7 car HCMT have?

Answer 9

Two

One in each Tc car

Question 10

What does the Auxiliary Compressor do?

Answer 10

Raises pantographs when:

There is insufficient MR pressure

When car has been isolated from MR

Question 11

Where is Auxiliary Compressor located?

Answer 11

DMp cars

If pantograph isolating cock is isolated on DMp car the pantograph will not be isolated. they will remain raised in the absence of MR air

Pg. 13

Question 12

What Air Reservoirs are there on a HCMT

Answer 12

Main Reservoirs

Surge Reservoirs - supplies air to airbag, one for every air bag

Brake Supply reservoirs

Question 13

What does the Brake Supply Reservoir do?

Answer 13

Supplies compressed air to the EP valves in the BCM to charge the BCs

Question 14

How can pantographs be raised? (2)

Answer 14

MR pressure above 700kPa

Battery operatedAuxiliary compressor when insufficient MR pressure

Question 15

How many pantograph ICs are there on DMp and Mp cars?

Answer 15

Saloon

and

Underframe

Question 16

Which will isolate the pantograph on a DMp car?

Answer 16

Saloon

Question 17

How can you reset the Trip?

Answer 17

Trip Reset switch on OJT panel

Trip rest plunger on the front of the trip

Question 18

How do you isolate the Trip?

Answer 18

Turn Trip IC on B side between doors 2 and 4 on Tc car

and

Turn Trip Bypass switch in drivers cab to isolate

Question 19

If you isolate the Trip what comes into play?

Answer 19

Safety System Bypass Acknowledgement button

Question 20

What is the Post trip Speed Restriction?

Answer 20

Activates automatically after Trip has been activated.

restricts speed of train to 25kmh

Assists drivers to comply with extreme caution rule

Question 21

How long does the Post Trip Speed Restriction apply?

Answer 21

500 seconds

Question 22

How do you cancel Post Trip Speed Restriction?

Answer 22

Press Trip Speed button (under tamper cover) when relevant safe working conditions have been complied with

Question 23

What are the ICs in the BCM?

Answer 23

Brake Supply

BC End 2

BC End 1

Tread Scrubber (Tc only)

Park Brake (not Tc)

Sanders

Question 24

Where is the sanding equipment located?

Answer 24

Question 25

Where are Tread Scrubbers located?

Answer 25

Wheel 3 and 4 on Tc cars

Question 26

What do the Tread Scrubbers do?

Answer 26

Clean debris from wheel face to ensure proper conductivity of the track circuit

Question 27

What type of brakes does each car have? Out of holding, emergency, parking, ED and EP

Answer 27

Question 28

Where is the BCU?

Answer 28

Inside the BCM

Question 29

What does the BCU do?

Answer 29

Controls the application and release of EP friction braking

Question 30

Where is the TCU?

Answer 30

Inside the VVVF Cabinet

Question 31

What does the TCU do?

Answer 31

Controls application of traction power and ED braking

Question 32

In emergency, what braking is used?

Answer 32

BCU takes over and friction EP braking only

Question 33

How does friction braking work?

Answer 33

Main Res. air via BCM to Brake Supply Reservoir back through BCM to BCs - compressed air pushes brake pads onto discs

Question 34

What ICs can isolate EP Friction brakes? (3)

Answer 34

Saloon Brake Supply IC (B06, door 4, every car) BCM - BC ICs (one per bogie) BCM - Brake Supply IC (one per car)

Question 35

What is the Holding Brake speed threshold?

Answer 35

0.5kmh

Question 36

When will emergency brake apply? (9)

Answer 36

Question 37

How do you reset safety loop?

Answer 37

Train stationary for more than 3 seconds Reason for emergency brake application reset MCH to MAX BRAKE Reverser to NEUTRAL

Question 38

Where are the two Park Brake Isolating cocks?

Answer 38

Saloon - cabinet B07 near door 3 BCM IC